What type of doors are designed to resist as much pressure as the bulkheads?

Watertight doors are specifically designed to maintain the integrity of a vessel's hull by preventing water from passing through to other compartments. These doors are built to withstand significant pressure from water, similar to the bulkheads they are installed in. This is crucial for a vessel's safety, as it helps to ensure that if one part of the ship is compromised, the rest of the vessel can remain buoyant and functional.

Hinged doors and sliding doors, while functional for access, do not have the same pressure-resisting capabilities as watertight doors and are not typically used in areas where water intrusion could be catastrophic. Fire doors, on the other hand, are meant to prevent the spread of fire and do not have the necessary design features to resist water pressure or flooding in the same way that watertight doors do. Therefore, the option of watertight doors is the most appropriate choice when it comes to being able to resist as much pressure as the bulkheads.